Voltage Quality Improvement for Hybrid Energy Storage of DC Microgrid

DC microgrids (MGs) have recently garnered significant interest due to their efficient power conversion and simpler control systems compared to AC MGs. However, managing DC MGs presents specific challenges, especially when dealing with pulsed power loads and constant power loads, as both require rapid dynamic responses from the MG, impacting voltage quality. This paper introduces a novel control methods, including a highpass filter with model predictive control (MPC) for current distribution between the battery and supercapacitor (SC) and a neuro-fuzzy system, to address these issues. These methods adjust the SC's state of charge (SoC) following abrupt load changes and maintain its SoC within a predefined range to ensure continuous operation. Using the proposed feedback neuro-fuzzy technique, the MG can improve voltage quality and transient response, achieving results that are nearly identical to those of the MPC. Simulations conducted in MATLAB/Simulink confirm the effectiveness of this approach.